The cellmate was a parole violator who had been sentenced to two years in prison for failing to register as a sex offender, according to a prison report. A cause of death was pending.

Prison officials have named Son as the suspect, but officials said charges against him will await the completion of the investigation.

Son, who played henchman Random Task in "Austin Powers: International Man of Mystery," was also briefly a mixed martial arts fighter who used the name Joe Son.

He had arrived at the prison reception center Sept. 16 after having been convicted of torture and sentenced to life in prison without parole in connection with the 1990 Christmas Eve rape of a woman out walking her dog.

Prosecutors in the torture case said the woman was walking back to her apartment alone with her dog after going to look at Christmas lights with a relative and friend and was stopped by Son about 12:30 a.m. on Christmas Eve 1990.

Son asked her for directions and then, with another man, dragged her to a car, threw her in the back and drove away.

Son and the other man told her they were driving to Compton, pistol-whipped her and repeatedly threatened to kill her.

Afterward, Son threatened to kill the victim and counted the bullets in the gun out loud as she pleaded for her life.

Son and Gaitan finally allowed the woman, identified only as Jane Doe, to leave, naked and with her pants tied around her eyes. The woman went to a nearby Huntington Beach home, where the residents called police.

While physical evidence was gathered in the case from the sexual assault, the case went cold. Son, however, was convicted in May 2008 of felony vandalism in an unrelated case and was forced to give a DNA sample.

That sample was then linked to DNA collected in the 1990 case, prosecutors said.

Gaitan pleaded guilty in January to kidnapping, sodomy, rape, forcible oral copulation and forcible rape with a sentencing enhancement for committing rape while armed with a firearm. He was sentenced to 17 years and four months in state prison.